What Drunk Rodents Can Tell Us About Human Relationships

A monogamous couple of
prairie voles, a male and female, are seen with their offspring
at Yerkes National Primate Research Center in Atlanta, Ga., in
2008.AP Photo/Emory University, Todd
Ahern

It seems alcohol makes the heart grow fonder, if you're a female
prairie vole. Researchers have found for the first time that
alcohol affects the brain systems involved in social bonding
differently for males and females.

Because prairie voles are known to mate for life, both in the
wild and the lab, the rodents are often used as a model to
understand the neurochemistry in human brains that leads us to
form lifelong relationships.

The small fuzzy creatures also make useful lab models of human
addiction behavior due to their social nature and taste for
alcohol (they even prefer it over water).

A boozy encounter

In this study, female and male voles were partnered up and given
access to tubes containing ethanol and water or only water. After
24 hours of hanging out together, the paired prairie voles were
separated and moved to different cages. Later, the researchers
tested their "preference" for either their drinking mate or an
unknown vole.

The alcohol affected the females differently than males.

The authors found that the alcohol made the females more likely
to pair-bond with their drinking partner than the females that
only drank water. Conversely, alcohol made the males less likely
to bond with their original partner after the boozy episode.

These differences in behavior seemed to be dictated by changes in
the brain to systems involved in social and anxiety-like
behaviors — the same ones that dictate the formation of the
voles' monogamous relationships.

The researchers note in the paper that the lower likelihood of
males to pair-bond when drinking is reminiscent of
the negative effects of alcohol on long-term attachments and
marital happiness in humans — suggesting that there could be
a biological element at play.

"These findings allow us to understand the factors involved in
regulations of social behaviors, and the effects of alcohol on
them, better," the study authors wrote in their paper.
"Identification of these factors can help develop better ways to
prevent or treat the devastating effects of alcohol abuse on
social relationships."